Performance Considerations

The following specifies tips about optimizing performance. This gives you an overview of which operations contribute to performance optimization.

• Restriction of selected rows

  The number of selected rows can be restricted by the following operations:

  • Setting Selection Options

  • Complex Conditions

  • View parameter (see External Views)

  • Checking Authorizations

  • Text Search Across the Whole Table

  • Setting filters on the UI (see Evaluation of the Concepts of the ALV Flavors)

• Restriction of selected columns

  Since every round trip triggers a new request to the database, it is not necessary for all columns to be read at the start of the display. From a previous SELECT * in the code of the application program, the ALV can restrict itself to the fields that are currently visible (see Visible Columns). All available fields are read only if no preselection about the display has been made (see Available Columns).

• Grouping Data

  With ALV with IDA the API enables you to display the data first as a group, with or without subtotals. For a grouping without subtotals all grouped rows with the exception of the first row are initially displayed collapsed. The first group is expanded up to its first level, but for detail records all their levels are displayed. Thes steps do not apply for a grouping with subtotals. Only when the rows are expanded further are the detail records read from the database. This procedure optimally supports the GROUP BY language element of a SELECT statement.

  See also: Initial Sorting, Grouping, and Aggregation

• Activation of country-specific sorting (umlauts)

  Country-specific sorting costs time and must be activated using the field catalog. This make sense in particular when no umlauts are expected (for example, in material codes that are stored in a non-numerical column).

  See also: Defining the Sort Strategy.

• Filters

  As with a grouping, filtering also directly influences the data amount in SAP List Viewer with IDA. The filter forms the WHERE clause of the ALV internal SQL statement, for example, which is sent to the database.